This invention relates to an active optical connector incorporating a light transmission module, whose transmission line is constituted by optical fibers.
An opto-electrical connection system using an optical fiber as a transmission line has an advantage that it is hardly influenced by noise interference.
In such a system electric signals are transformed at first into optical output signals by means of a light emitting element coupled to a first electric connection device and the optical signals thus obtained by transformation are transmitted through the optical fibers to a light receiving element in a second connection device, in which they are transformed again into electric signals.
U.S. Pat. No. 3,809,908 discloses an electro-optical transmission line used in the system stated above. According to this reference, connecting means mounted at the two extremities of a transmission line including optical fibers are used substantially as electric connectors, by which a light emitting element and a contact terminal connected electrically with the light emitting element are mounted at one end of an optical fiber, and a light receiving element and a contact terminal connected electrically with the light receiving element are mounted on the other end of the optical fiber.
However, although according to this prior art, the optical fiber can be considered practically as an electric part owing to the contact terminals mounted at the two extremities of the line, for the following technical reasons it cannot be said that it is a perfect electric part. That is, a driving circuit is necessary for driving the light emitting element and an amplifier circuit is required in order to utilize weak electric signals coming from the light emitting element as output signals.
Heretofore, such a driving circuit and an amplifier circuit are disposed at the main part of an apparatus connected with the contact terminal stated above. In the case where the manufacturer of the device, in which the contact terminal and the optical fiber are combined, is different from the user (maker of the main part of the apparatus), which uses the combined device, it necessitates special consideration by which attention should be paid to optical signals in the design of the main part of the apparatus such that a circuit for processing the optical signals should be disposed at the main part side of the apparatus. Consequently, it cannot be said that the prior art electro-optical transmission line described above is a perfect electric part.